Dual pendulum valve assembly

Abstract

A dual pendulum valve assembly including a housing having an interior space and first and second openings through which fluid can enter and exit the interior space; valve seats disposed in the interior space around the edges of the openings; and first and second pendulum valves for opening and closing, respectively, the first and second openings. Each pendulum valve is independently movable and includes a valve body mounted relative to the housing so that the valve body is movable between a completely opened position wherein fluid is allowed to pass through its respective opening and a completely closed position wherein the valve body seals the opening so that fluid can not pass therethrough. Each pendulum valve also includes a shaft fixedly coupled to the valve body through at least one pivot arm and at least partially mounted within the housing so that the valve body can rotate about a longitudinal axis of the shaft between a first angular position where the first valve body is in the completely opened position and a second angular position where the valve body is substantially axially aligned with its respective opening, and move substantially parallel to the longitudinal axis of the shaft, so that the valve body can move between the second angular position and the completely closed position as the pendulum valve continues to rotate. The present disclosure also provides a method of precisely controlling vacuum pressure within a process chamber of a semi-conductor wafer fabricator.

Description

FIELD OF THE DISCLOSUREThe present disclosure relates to gate valve assemblies, and more particularly to a dual pendulum valve assembly comprising a process chamber isolation valve and a vacuum pump isolation valve. The vacuum pump isolation valve is useful for isolating a vacuum pump coupled to the pendulum valve assembly so that the vacuum pump is not exposed to the atmosphere during cleaning of the pendulum valve assembly and process chamber.BACKGROUND OF THE DISCLOSUREA pendulum valve assembly generally includes a housing containing a pendulum valve and including an interior space and a pair of openings through which gaseous fluid can enter and exit the interior space. As its name implies, a pendulum valve pivots between open and closed positions, and includes a valve body, which is usually provided as a disk, connected to a rotatably shaft by a pivot arm. In a completely opened position the disk of the pendulum valve is moved out of the flow path defined by the openings so that...

AI Technical Summary

Benefits of technology

Each pendulum valve is independently movable and includes a valve body mounted relative to the housing so-that the valve body is movable within the interior space between a completely opened position wherein fluid is allowed to pass through its respective opening and a completely closed position wherein the valve body engages the valve seat around its respective opening and seals the opening so that fluid can not pass therethrough. Each pendulum valve also includes a shaft fixedly coupled to the valve body through at least one pivot arm and at least partially mounted within the housing so that the valve body can rotate about a longitudinal axis of the shaft between a first angular position where the first valve body is in the completely opened position and a second angular position where the valve body is substantially axially aligned with its respective opening, and move substantially parallel to the longitudinal axis of the shaft, so that the valve body can move between the second angular position and the completely closed position as the pendulum valve continues to rotate.

The dual pendulum valve assembly disclosed herein preferably utilizes simple rotating cam mechanisms that precisely controls the rotational and axial movement of the valve bodies between their completely opened and completely closed positions.

The present disclosure also provides a method of precisely controlling vacuum pressure within a process chamber of a semi-conductor wafer fabricator utilizing the dual pendulum valve. The method includes connecting the vacuum pump to the process chamber through the first and the second openings of the valve housing, respectively, and operating the vacuum pump to create a first pressure within the process chamber.

Problems solved by technology

In order to obtain this combination of rotational and translational movement, prior pendulum valves have typically used multiple actuator elements which are inherently difficult to effect precise movement of the disk, and therefore more difficult to utilize for precise flow control purposes.

Since the vacuum pump contains residues from the process conducted within the process chamber, venting to atmosphere exposes these residues to water vapor and other contaminants that may react with the residues to produce a corrosive agent that can lead to corrosion and premature failure of the vacuum pump.

When the aluminum trichloride residue reacts with water vapor in the atmosphere, an extremely corrosive hydrochloric acid (HCl) is produced.

As is known, such vacuum pumps are very expensive and difficult to replace.

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